Lipid peroxidation and antioxidant systems in rat brain: effect of chronic alcohol consumption

The effect of chronic ethanol exposure, in a liquid diet, on lipid peroxidation and some antioxidant systems of rat brain was investigated. Chronic ethanol administration induced a greater susceptibility to iron/ascorbate-induced lipid peroxidation, estimated as thiobarbituric reactive substances (TBARS) production, in the microsomal fraction, but a lower lipid peroxidation in the total homogenate. Glutathione (GSH) levels as well as GSH peroxidase and GSH reductase were unaffected, while the activity of Cu-Zn superoxide dismutase was decreased and that of catalase increased. Lipid peroxidation experiments performed in the presence of some hydroxyl radical scavengers suggested that a greater OH. generation may be responsible of the greater TBARS production in the microsomal fraction of ethanol treated rats; differently, in total homogenate of control and ethanol rats a relationship was found between the redox state of iron and TBARS production, suggesting that the lower lipid peroxidation in treated rats may depend on a different modulation of the iron redox state.